This dataset describes dust particle size of two marine sediment records in the Southern Ocean. The first record is South-Pacific core PS75/056-1 (55.16°S, 114.78°W; at 3581m water depth), recovered during R/V Polarstern expedition ANT-XXVI/2, PS75 (Gersonde, 2011). Samples from 0.07-9.93 m core depth were analysed (N=183), and grain sizes were analysed with the laser particle sizer Beckmann Coulter LS13 320 at NIOZ, The Netherlands. This record spans the last ~260 kyr. The second sediment record is ODP Site 1090 (42.91°S, 8.90°E, at 3702m water depth), recovered during the Ocean Drilling Program Leg 177 expedition (Gersonde et al., 1999). Samples from 0.00-4.84 m were analysed (N=333), and grain sizes for ODP Site 1090 were analysed with the laser particle sizer Malvern Mastersizer 2000 at ETH Zurich, Switzerland. This record spans the last ~160 kyr. For both records, grain-size analyses were performed on the isolated terrigenous fraction, after the biogenic components (organics, carbonates and biogenic opals) were removed. In addition, different size fractions were determined, and the mean grain sizes of four size fractions were calculated using the program GRADISTAT (Blott & Pye, 2001).